Stock enhancement by hatchery-released turbot, Psetta maxima, in the southeastern Black Sea: capture, migration, growth and diet analyses

Abstract

In this study, the capture, growth, migration and diet of hatchery-released turbots (Psetta maxima) were examined in the southeastern Black Sea region for six years (2009-2014). A total of 9933 turbots were marked with individual serial-numbered T-bar anchor tags and released at Trabzon, Turkey. The mean TL and weight of the released turbots were 12.91 cm (±1.25) and 35.41 g (±12.38) and the same measurements for the captured turbots were 31.17±0.86 cm and 878.08±69.47 g, respectively. A total of 2.7% (270 fishes) of the tagged individuals were captured during the study period and the age of the captured tagged fishes was between 0+ and 5+ years. Growth of the captured turbots was analytically examined. Movements of the tagged turbots were expressed as “resident” and “migratory”. Three prey groups showed the majority of forage organisms; teleost fishes, crustaceans and mollusks in the stomach of the captured turbots. The hatchery-released turbots might be used for stock enhancement due to their high growth rate and commercial value, and their relatively limited migration range.

Keywords

• turbot
• stock enhancement
• tagged
• capture
• growth
• migration
• feeding
• black sea